TI TPS5432DDAR

TPS5432是一款集成MOSFET的6V、3A、低静态电流(Iq)、电流模式同步单片降压转换器。 TPS5432通过集成MOSFET、采用电流模式控制来实现小型化设计，从而减少外部元件数量；700kHz开关频率有助于缩小电感尺寸。带外露散热垫的SOIC-8封装提供增强散热解决方案，且易于使用。 TPS5432在整个温度范围内提供精确电压基准（3.0%），实现对多种负载的精确调节。 集成70mΩ MOSFET与典型值360μA的电源电流显著提升了效率。通过使能引脚进入关断模式后，关断电流可降低至2μA。 输出电压启动斜坡由慢启动引脚控制。在该引脚上连接一只陶瓷电容器即可方便地调节慢启动时间。 频率折返与热关断功能在过流条件下保护器件免受损坏。

The TPS5432 is a 6-V, 3-A synchronous step-down (buck) converter with two integrated n-channel MOSFETs. To improve performance during line and load transients, the device implements constant frequency, peak current mode control, which reduces output capacitance and simplifies external frequency compensation design. The fixed switching frequency of 700kHz provides the balance between efficiency and size of the output filter components. The TPS5432 has a typical default start-up voltage of 2.6 V. The EN pin has an internal pull-up current source that can provide a default condition when the EN pin is floating for the device to operate. The total operating current for the TPS5432 is typically 360μA when not switching and under no load. When the device is disabled, the supply current is less than 5μA. The integrated 70mΩ MOSFETs allow for high efficiency power supply designs with continuous output currents up to 3 amperes. The TPS5432 reduces the external component count by integrating the boot recharge diode. The bias voltage for the integrated high side MOSFET is supplied by a capacitor between the BOOT and PH pins. The boot capacitor voltage is monitored by an UVLO circuit and turns off the high side MOSFET when the voltage falls below a preset threshold. The output voltage can be stepped down to as low as the 0.808 V reference. The TPS5432 minimizes excessive output over-voltage transients by taking advantage of the over-voltage comparator. When the regulated output voltage is greater than 107% of the nominal voltage, the over-voltage comparator is activated, and the high side MOSFET is turned off and masked from turning on until the output voltage is lower than 105%. The SS (slow start) pin is used to minimize inrush currents during power up. A small value capacitor should be coupled to the pin for slow start. The SS pin is discharged before the output power up to ensure a repeatable restart after an over-temperature fault, UVLO fault or disabled condition. The use of a frequency fold-back circuit reduces the switching frequency during startup and over current fault conditions to help limit the inductor current.

• Two 70mΩ (typical) MOSFETs for 3A continuous output current
• Current mode control with external compensation
• 700kHz switching frequency
• 360μA no-load quiescent current (no switching)
• Internal voltage reference: 0.808V
• ±2.0% reference accuracy at 25°C
• ±3.0% reference accuracy over -40°C to 125°C temperature range
• Stable operation with ceramic output capacitors
• Adjustable soft-start
• Cycle-by-cycle current limiting and frequency foldback protection
• Thermally enhanced 8-pin SOIC (DDA) package

• Consumer applications such as DTV, set-top boxes, LCD monitors, and CPE
• Low-voltage point-of-load regulation for SoC, CPU, and DSP